US: Blueberry tree research could help growers branch out

Wei Qiang Yang, blueberry agent for the Oregon State University Extension Service, has tested a grafted blueberry "tree" that grows on a single stem on a research plot at OSU's North Willamette Research and Extension Center in Aurora every year since 2009. Yang is collaborating with researchers who are testing other blueberry varieties grafted onto rootstocks at land-grant universities in California and Florida as part of a multi-state effort.

"The first rootstock that will come out of this research for commercial use will significantly change the way blueberries are currently produced and harvested," said Yang, a horticulture professor in OSU's College of Agricultural Sciences.

Growers use machine harvesters with catch plates to collect blueberries, but because blueberry bushes have multiple stems, the catch plate cannot fully encircle each stem of the bush. So growers must bear about a 15-25 percent loss in terms of the fruit that the catch plate misses, according to Yang. But cultivating a blueberry bush in a tree form would change that, he said.

Yang must still analyze results of data collected on fruit quality factors such as firmness, size and total acidity. This is the first year researchers were able to collect data on yield for the project in Oregon. Yang will investigate future yield projections and machine harvesting potential next. If results continue to show promise, the blueberry tree could be ready for release to nurseries in approximately five years for commercial use and about three years for gardeners.

Though some people have tried grafting blueberry trees on a small-scale basis in the past, Yang said this is the first major collaborative research effort to graft a blueberry tree that is viable for commercial growers.